THE DESQUAMATION AND DIGESTION OF SERPENTS 53 



than one-fourth of its whole surface, it dies with shiverings, 

 exacerbation of temperature, and other evidence of blood- 

 poisoning, innocent as the constituents of the sebaceous and 

 sudoriferous secretions appear to be. The chief point which I 

 would advance in favour of this physiological and pathological 

 analogy— for of course I do not compare the minute structure of 

 the skin or its glandular appendages with that of a mammal — is 

 that the slough, if examined during the time of its actual 

 separation or immediately afterwards, is found to have a slight 

 but well-defined acid reaction. "What the nature of this acid may 

 be I have had no means of ascertaining, nor should I in all 

 probability be a sufficiently competent chemist to discover, even 

 if I had the appliances for analysis at hand ; for there can be no 

 doubt, judging from its instability and rapid decomposition, that 

 it is some very complex organic compound. Its disappearance is 

 not dependent on simple evaporation or the drying of the slough. 

 This instability and another reason which I shall mention 

 presently in the second part of this paper preclude the possibility 

 of its being uric acid, while experiment has demonstrated that it 

 is not lactic or any other of the acids which commonly result from 

 chemical changes in the tissues. 



Furthermore, this exudation seems to be preceded by a rise 

 of temperature, and accompanied by its remission — precisely 

 similar to what would occur under parallel circumstances in more 

 highly organized beings; but this last is a statement which I 

 make guardedly and with some reserve, and should be glad of 

 more certain information on that head from those who have 

 better opportunities for observation than I have. Nearly all my 

 experiments have been conducted at sea, where it is extremely 

 difficult to register minute variations of temperature with accuracy. 

 I believe that I have obtained an increase constantly, but, as 

 might be imagined, the difference is very small, and the operation 

 of taking it and guarding the thermometers from surrounding 

 influences one of great delicacy and difficulty. 



The excrement (for there is but one) of a serpent in health 

 may be said to consist of three parts — 1st, a dark mass, made up 

 of the indigestible residue of its food, feathers, hair, claws, teeth, 

 seeds or other vegetable matters from the stomachs, easily dis- 

 tinguishable with the naked eye, mixed with microscopic particles 

 of the same, and a variable amount of digestible but undigested 



